We have designed and tested a portable gated‐Raman system that is capable of detecting organic and inorganic bulk chemicals over stand‐off distances of 100 m and more during day and night time. Utilizing a 532 nm laser pulse
Raman spectra of several organic and inorganic compounds have been measured with the portable Raman instrument over a distance of 100 m. Remote Raman spectra, obtained with a very short gate (2 micro second), from a variety of inorganic minerals such as calcite
α‐quartz (α‐
), barite
and
and organic compounds such as acetone, methanol, 2‐propanol and naphthalene showed all major bands required for unambiguous chemical identification. We also measured the Raman and fluorescence spectra of plant leaves, tomato, and chicken eggshell excited with a 532 nm, 20 Hz pulsed laser and accumulated over 200 laser shots (10‐s integration time) at 110 m with good signal‐to‐noise ratio. The results of these investigations show that remote Raman spectroscopy over a distance of 100 m can be used to identify Raman fingerprints of both inorganic, organic, and some biological compounds on planetary surfaces and could be useful for environmental monitoring.

Various mid‐infrared (MIR) and Raman spectroscopic methods applied to the analysis of valuable plant substances or quality parameters in selected horticultural and agricultural crops are presented. Generally, both spectroscopy techniques allow to identify simultaneously characteristic key bands of individual plant components (e.g. carotenoids, alkaloids, polyacetylenes, fatty acids, amino acids, terpenoids). In contrast to MIR methods Raman spectroscopy mostly does not need any sample pre‐treatment; even fresh plant material can be analysed without difficulty because water shows only weak Raman scattering
properties. In some cases a significant sensivity enhancement of Raman signals can be achieved if the exciting laser wavelength is adjusted to the absorption range of particular plant chromophores such as carotenoids (Resonance Raman effect). Applying FT‐IR or FT Raman micro‐spectroscopy the distribution of certain plant constituents in the cell wall can be identified without the need for any physical separation. Furthermore it is also possible to analyse secondary metabolites occurring in the cell vacuoles if significant key bands do not coincide with the spectral background of the plant matrix.

Far‐IR spectra with a synchrotron radiation
source were for the first time recorded through a microscope coupled to an FTIR‐spectrometer. A comparison with spectra recorded with an ordinary globar source revealed that no artifacts occurred with synchrotron radiation. A comparison of ATR (Si‐prism) and transmission spectra of a tetrapeptide showed that the ATR‐microscope technique could be applied. ATR‐ and transmission spectra were recorded of polyglycine and compared to the low wavenumber Raman spectrum in the
‐representation. A protein band at
was assigned to hydrogen bond modes. Collectively these modes might drive conformational changes in proteins. Based mainly on previously published results the determination of water with a structure like that in bulk liquid water was performed for human and animal skin samples. Changes in water content were reported for freezing and thawing of human skin biopsies and for human skin with benign or malignant skin diseases.

Unfolded proteins are generally thought to be structurally random with a minimum of non‐local interactions. This concept implies that with the exception of glycine and proline the conformational propensities of amino acid residues in polypeptides should be comparable in that they all sample the statistically allowed region of the Ramachandran plot. However, over the last ten years experimental and computational evidence has emerged for the notion that the conformational space of residues might be more restricted than predicted by random or statistical coil models. We have developed several algorithms which can be used to simulate the amide I band profile of the IR, isotropic Raman, anisotropic Raman and Vibrational Circular Dichroism (VCD) spectra of polypeptides based on assumed ensembles of side chain conformations. The simulations are generally restricted by
coupling constants obtained from NMR spectroscopy. A comparison with experimental results reveals that e.g. alanine has a clear preference for the so called polyproline II (PPII) conformation in short peptides. The situation becomes more complex if longer polyalanines are doped with negatively charged residues. For the so‐called XAO‐peptide (
X: diaminobutyric acid, O;ornithine) we found a more compact structure owing to multiple turn conformations sampled by the
interfaces. For Salmon Calcitonin, a 32‐residue hormone, we identified a mixture of PPII, β‐strand and helical conformations. Currently, we are in the process of investigating short GxG (x; different natural amino acid residues) peptides in terms of conformational distributions obtained from coil libraries. This will enable us obtain the conformational preferences of amino acid residues in the absence of nearest neighbor interactions.

This contribution aims at the dynamic aspects of peptide
conformation in aqueous solution where peptide
structural
properties are most relevant to their biological role. In order to obtain solid physical knowledge about peptide
structure and dynamics, we proceeded from simple amino acids and model dipeptides to more complex systems. Experimentally the project is based mainly on Raman Optical Activity (ROA) and Raman scattering that can sense equilibrium distributions of rapidly fluctuating structures. Interpretation of Raman and ROA spectra is based on advanced spectral simulations taking into account conformational flexibility of the studied systems as well as solvent effects. Force fields and polarizability tensors of longer peptides are constructed from short fragments by means of atomic tensor transfer. The ultimate goal is to fill the gap between the knowledge of simple dipeptides and proteins and bring detailed interpretation of the peptide
spectra.

A selection of model systems for the chromophores present in vision
proteins (opsins) and the Green Fluorescent Protein (GFP) was synthesized and their intrinsic optical properties were investigated in the gas phase. These investigations have provided fundamental knowledge on protein‐chromophore interactions. Thus, opsins induce a blue‐shift in the absorption maximum of the retinal Schiff base chromophore, while red‐ and blue‐shifting interactions between GFP and its chromophore cancel out.

Diabetes mellitus is a chronic disorder, affecting nearly 200 million people worldwide. Acute complications, such as hypoglycemia, cardiovascular disease and retinal damage, may occur if the disease is not adequately controlled. As diabetes has no known cure, tight control of glucose levels is critical for the prevention of such complications. Given the necessity for regular monitoring of blood glucose, development of non‐invasive glucose detection devices is essential to improve the quality of life in diabetic patients. The commercially available glucose sensors measure the interstitial fluid glucose by electrochemical detection. However, these sensors have severe limitations, primarily related to their invasive nature and lack of stability. This necessitates the development of a truly non‐invasive glucose detection technique. NIR Raman Spectroscopy, which combines the substantial penetration depth of NIR light with the excellent chemical specificity of Raman spectroscopy, provides an excellent tool to meet the challenges involved. Additionally, it enables simultaneous determination of multiple blood analytes. Our laboratory has pioneered the use of Raman spectroscopy for blood analytes’ detection in biological media. The preliminary success of our non‐invasive glucose measurements both in vitro (such as in serum and blood) and in vivo has provided the foundation for the development of feasible clinical systems. However, successful application of this technology still faces a few hurdles, highlighted by the problems of tissue
luminescence and selection of appropriate reference concentration. In this article we explore possible avenues to overcome these challenges so that prospective prediction accuracy of blood analytes can be brought to clinically acceptable levels.

Pathways of vibrational energy flow in molecules with an intramolecular hydrogen bond are studied after intramolecular proton transfer reactions as well as after infrared excitation of the O–H stretching vibration which is coupled to this hydrogen bond.

The use of four‐wave mixing techniques in femtosecond time‐resolved spectroscopy has considerable advantages. Due to the many degrees of freedom offered e.g. by coherent anti‐Stokes Raman scattering
(CARS), the dynamics even of complex systems can be analyzed in detail. Using pulse shaping techniques in combination with a self‐learning loop approach, molecular mode excitation can be controlled very efficiently in a multi‐photon excitation process. Results obtained from the optimal control of CARS on β‐carotene are discussed.

The complexation ability and the binding mode of the ligand coumarin‐3‐carboxylic acid (HCCA) to La(III), Ce(III), Nd(III), Sm(III), Gd(III) and Dy(III) lanthanide ions (Ln(III)) are elucidated at experimental and theoretical level. The complexes were characterized using elemental analysis, DTA and TGA data as well as
NMR and
NMR spectra. FTIR and Raman spectroscopic techniques as well as DFT quantum chemical calculations were used for characterization of the binding mode and the structures of lanthanide(III) complexes of HCCA. The metal—ligand binding mode is predicted through molecular modeling and energy estimation of different Ln—CCA structures using B3LYP/6‐31G(d) method combined with a large quasi‐relativistic effective core potential for lanthanide ion. The energies obtained predict bidentate coordination of
to Ln(III) ions through the carbonylic oxygen and the carboxylic oxygen. Detailed vibrational analysis of HCCA,
and Ln(III) complexes based on both calculated and experimental frequencies confirms the suggested metal—ligand binding mode. The natural bonding analysis predicts strongly ionic character of the Ln(III)‐CCA bonding in
complexes studied. With the relatively resistant tumor cell line K‐562 we obtained very interesting in‐vitro results which are in accordance with our previously published data concerning the activity of lanthanide(III) complexes with other coumarin derivatives.

The amino and phenyl units frequently constitute functional structural fragments in a variety of chemically and biologically interesting systems. Various pharmacologically active substances include methyl and amino groups as important constituents. The normal coordinate analysis of chloromethylanilines was carried out using a recently developed intra molecular force fields for chloromethylphenols and dimethylanilines. The potential energy surface function for three isomers of chloromethylanilines were obtained in terms of 24 principal force constants and 37 intramolecular force constants. It was observed that a single force field is able to simulate the observed normal vibrations in all the three molecules studied presently. The vibrational assignments are supported by HF and DFT calculations.

The Fourier Transform Raman and infrared spectra of the crystallized pharmaceutical molecule 1‐benzyl‐1H‐imidazole (BI) have been recorded and analyzed. The geometry, intermolecular hydrogen bond, and harmonic vibrational frequencies of BI have been predicted with the help of B3PW91 density functional theory
(DFT) methods. The vibrational spectra have been simulated with the aid of normal coordinate analysis (NCA) following the scaled quantum mechanical force field methodology (SQMFF). The pronounced double‐bond derealization in the imidazole ring upon intermolecular H‐bonding becomes the cause for its enhanced aromaticity.

Vibrational spectral analysis of L‐Alanylglycine (L‐Ala‐Gly) is carried out using NIR FT‐Raman and FT‐IR spectroscopy, supported by density functional theory
(DFT) calculations to obtain the equilibrium geometry, bonding features and harmonic vibrational frequencies. The assignments of the vibrational spectra have been carried out with the help of normal coordinate analysis (NCA) following the scaled quantum mechanical force field methodology (SQMFF). Potential energy surface (PES) scan studies has also been carried out by
ab initio calculations with
basis set. The natural bond orbital (NBO) analysis confirms the occurrence of strong intermolecular hydrogen bonding in the molecule.

Femtosecond time‐resolved coherent anti‐Stokes Raman scattering (fs‐CARS) gives access to ultrafast molecular dynamics. However, femtosecond laser pulses are spectrally broad and therefore coherently excite several molecular modes. While the temporal resolution is high, usually no mode‐selective excitation is possible. This paper demonstrates the feasibility of selectively exciting specific molecular vibrations in solution phase with shaped fs laser excitation using a feedback‐controlled optimization technique guided by an evolutionary algorithm. This approach is also used to obtain molecule‐specific CARS spectra from a mixture of different substances. The optimized phase structures of the fs pulses are characterized to get insight into the control process. Possible applications of the spectrum control are discussed.

Surface enhanced Raman spectroscopy have provided potential tool for the detection of organic/biological molecules within the cell of living organism. This technique is suitable for in vivo as well as in vitro detection upto single molecular level. In the present work we have studied SERS activity of zinc
nanoparticles on
and
molecules. Colloidal solution of zinc
nanoparticles was found as a suitable substrate for Raman signal enhancement. The applied technique may be useful for the sensing of organic/biological molecules as a trace in solid as well as in liquid media.

Surface enhanced Raman scattering based optical sensing (SERS‐OS) is one of the most powerful techniques for the sensitive and selective detection of low concentration analytes. Mostly, metallic nanoparticles, such as Ag,
Au and Cu, are used as substrate materials in this technique. Present work is concerned with the possibility of utilization of colloidal
zinc
nanoparticles, produced by pulsed laser
ablation method, as substrate material in SERS‐OS.

Vibrational spectra of 5‐nitro‐6‐methyluracil have been investigated using quantum chemical density functional calculations, FT‐IR
and Raman
spectra. Harmonic vibrational frequencies were calculated by DFT (B3LYP) method using the basis sets 6‐31G and 6‐311G and compared with the experimental ones. The vibrational band compositions of various modes are reported.

Fourier‐Transform Laser Raman
and Infrared
spectral
measurements have been made for the solid 3‐Chloro‐4‐hydroxybenzaldehyde. Electronic ground state energy, equilibrium structure, harmonic vibrational frequencies, depolarization ratios, force constants and normal modes have been computed at two levels of theory, namely, Restricted Hartree‐Fock (RHF) and Becke’s three parameter‐hybrid functional combined with Lee‐Yang‐Parr correlation (B3LYP) combined with 6‐31G* basis set. Potential energy distributions (PEDs) and normal mode analysis have been performed. The orientation of C=O of aldehydic group with respect to the hydroxyl group and chlorine in the Cis form is found to be the most stable. Of the aldehydic frequencies, the C=O stretching vibration observed at
is predicted at
the C–H vibration observed at
is predicted at
A broad IR band near
shows the evidence of hydrogen bonding, O–H…O. A good agreement between theoretical and experimental spectra is observed. A complete assignment of the observed spectra, aided by the theoretical results and normal modes has been proposed.

The absorption spectra of halogen substituted benzenes have been studied in its pure form in the
region. Large number of bands involving fundamental, C–H overtones and combination bands has been observed. Vibrational frequencies, anharmonicity constants and dissociation energies, for the C–H stretch vibrations have been determined using local mode model. The frequencies obtained are compared with the frequencies obtained theoretically using B3LYP/6‐311G* method. Effect of hydrogen atom substitution by chlorine and bromine atoms has been studied by measuring changes in the vibrational frequency and bond length of the C–H bond. Frequency changes have been well correlated with the change in charge density on the carbon as well as chlorine atoms.